1. Field of the Invention
The present invention relates to an endoscopic drill guide and, more specifically, to an endoscopic drill guide having an offset hook for properly locating the position to drill a tunnel for endosteal fixation of a substitute ligament or graft.
2. Description of the Related Art
When a ligament or tendon becomes detached from the bone, surgery is usually required to re-secure the ligament or tendon. Often, a substitute ligament or graft is attached to the bone to facilitate regrowth and permanent attachment. The reattachment procedure involves drilling of a graft tunnel between two bones, for example, the tibia and the femur.
To achieve optimal results, it is important that the graft tunnel be drilled at a particular angle and location through the tibia and femur. Ordinarily, an incision is made to access the proper area for drilling a tunnel through the tibia. A guide pin is placed through the incision and driven into the tibia. A drill is then placed over and guided by the guide pin during the drilling of the graft tunnel through the tibia.
A problem arises in locating the proper position for drilling the graft tunnel in the femur. The ideal location for the graft tunnel is 7 mm in front of the posterior aspect of the femoral notch. Ordinarily, the location for drilling the graft tunnel in the femur is determined in one of two ways.
The first method is to insert the guide pin through the incision and the graft tunnel in the tibia and into the femur. The drill is then placed over and guided by the guide pin during drilling of the graft tunnel in the femur. The problem with this method is that the femur is difficult to see through the graft tunnel in the tibia. Thus, determining the proper location for the graft tunnel in the femur must often be accomplished by guesswork.
The second method is to drill the graft tunnel in the femur in the opposite direction from the outside. Although this method is more accurate, it involves making a second incision which results in unnecessary fluid loss and an additional scar.
A further disadvantage of the above two methods is that neither permits testing of graft isometry or notch impingement prior to attachment of the graft. Such testing enables a more secure graft attachment, resulting in rapid healing and stronger regrowth.